Your first H1 report

This walkthrough takes you from a plan PDF to a consent-ready H1 report using the plan-first workflow and a sample assembly. Allow about fifteen minutes for a simple single-storey house. Each step links to the fuller guide for that task. (On your first visit, a short welcome tour walks through this same path in the app, with short screen recordings - re-enable it any time under Settings → Profile.)

You need a plan PDF with at least a floor plan and a roof plan, and a known dimension on the drawing (a stated room size or a scale bar) so you can calibrate.

Prefer to explore a finished job first?

Every account's Dashboard carries a read-only sample project ("123 Sample Street, Sampletown") - a complete take-off, assemblies, AI plan summary and AI Review over a demonstration plan. View sample to look around, or Copy to edit for your own editable copy to experiment on. A report generated from the sample is marked "Sample" and never counts against your allowance.

1. Create the project

From the Dashboard, click New H1 project, give it a name, and open it in the H1 Compliance page. More: Setting up a project.

2. Set the climate zone

In Project Information, set the Climate zone. Type the site's NZ postcode and Thermly looks up the zone, or pick one of the six H1/AS1 6th edition zones (Appendix C) directly. The zone selects the reference building your design is compared against. Not sure which zone applies? The free climate zone finder confirms it against the H1/AS1 territorial-authority table and can carry the confirmed zone into a new project.

3. Attach the plan

In Plan PDF (optional), attach the architectural plan set. The file uploads securely to your account and stays available to view and download whenever you reopen the project. More: Uploading and calibrating your plan.

Read the drawing set for you

With a plan attached, ✨ Read with AI on Project Information can pre-fill the site address, designer and consent reference from the drawing's title block, for you to check and correct. And ✨ AI plan summary on the plan card opens a floating window listing everything the drawing set states that helps complete the form - insulation specs, window and door schedules, floor construction - with the plan page each item was read from. Both are available on accounts with AI features enabled.

4. Calibrate the scale

Open the plan, pick the Calibrate tool, click two points on a known dimension, then enter the real distance. Everything you draw afterwards is measured against that scale.

Calibrate the page you are about to measure. A new diagram can inherit the scale from another page as a convenience, but if that page is plotted at a different scale the inherited areas will be wrong. Thermly tints an inherited scale amber and shows "Scale inherited from plan - re-calibrate for accurate areas" so you know to check it. See Re-calibration.

5. Take off the elements

This is the heart of the plan-first workflow, and it is walls-first. Using the toolbar (full detail in The plan take-off):

• Walls - use the Line tool to trace each wall run; length × stud height gives the wall area. On a vector plan, the optional Wall take-off assist (Settings → Plan markup) picks a complete run per click, straight off the drawing's line-work.
• Openings - with the Opening tool, click a wall to drop a window or door, then confirm its width × height - on most plans the number and size prefill from the drawing's own text call-outs. Openings net out of the wall area automatically.
• Roof and floor - once the walls are traced, click 🧱 From walls on the Roof and floor sections and Thermly derives them from the region your walls enclose - no re-tracing. Then set the Roof pitch so the sloped area is right. (You can always trace them yourself with Zone or Rectangle instead.)
• Skylights - with the Skylight tool, click the roof and enter the skylight size.

Each shape carries a live area readout as you draw, and each element gets its own plan colour and tag (WA1, RO1, FL1 …) so the drawing and the legend stay readable. When the take-off is done, click Save diagram - the marked-up diagram is embedded in your report.

6. Assign a sample assembly

Every element needs an assembly, and assemblies are assigned in the form view: each traced element appears as a row on the H1 page with a Choose an assembly… picker. To get a result straight away, assign one of the sample assemblies Thermly ships - for example "Vented attic, R6.0 ceiling insulation" for the roof, and a framed-wall sample for the walls.

The sample produces a correct calculation immediately. When you are ready to reflect the real build-up, build your own assembly (it is the same short layer-by-layer form) or swap products in place from the H1 page.

7. Read the verdict

The Heat-loss check footer shows PASS or FAIL and your headroom against the reference building, updating live as you change the design. If it fails, the per-element rows and the hard-rule checks show why. More: Reading the H1 report.

Run AI Review before you generate

The AI Review button in the report bar runs a free pre-flight over your inputs: gaps (no climate zone, missing elements), compliance blockers (failed minimums, the glazing cap), and risks (thin headroom, incomplete build-ups). On accounts with AI features, an AI pass also cross-checks your entries against the plan - the insulation spec vs your chosen build-ups, the window schedule vs your openings. Findings are advisory, each with a clause pointer to verify against; nothing from it prints on the report.

8. Fill in the details and generate

Complete Project Information (site address, consent reference, designer) - these appear on the report cover and headers. The report author comes from your Profile settings, so there is nothing to retype per project. Then click Generate H1 compliance report - the project saves automatically first, so the report always reflects a saved version; during open testing you accept the pre-release terms before the PDF is produced.

Thermly renders a PDF: the heat-loss result, the construction schedule and build-ups, the critical review items, your plan diagrams, and a declaration block for the preparer and reviewer to complete. Review it, satisfy yourself it is correct and complete for the building, and it is ready to attach to a consent application. More: Generating your H1 report.

9. Save

Generating already saved the project, so it is on your Dashboard; click Save as you make further changes. You can reopen, revise, and re-generate at any time.

What next

• Build real assemblies: Assemblies and products.
• Order the insulation: Generating your insulation take-off.
• Understand the numbers: How Thermly calculates compliance.